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	<title>Abouth LDBN</title>
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	<p>
	Database normalization is a technique for designing relational database tables to minimize
duplication of information in order to safeguard the database against certain types
of logical or structural problems, namely data anomalies. Therefore database normalization
is a central topic in database theory, and its correct understanding is crucial for
students. Unfortunately, the subject it is often considered to be dry and purely theoretical
and is often not well received by students. 
To help avoid some of the above problems LDBN was 
	developed by <a href="mailto:ens07ngv@cs.umu.se">Nikolay Georgiev</a> as 
	part of his master thesis at the University
	of Ume&aring;, Sweden, under the supervision of 
	<a href="http://www.cs.umu.se/~hegner/" target="_blank">Stephen J. Hegner</a>.
	The master's thesis report can be found <a href="http://www.cs.umu.se/education/examina/Rapporter/NikolayGeorgiev.pdf" target="_blank">here</a>.
	</p>
	<p>
	LDBN is a web-based environment for learning relational-database
	normalization. LDBN is aiming to improve the undersending and knowledge of 
	relational-database normalization among students, who are learning 
	database theory and are already familiar with the basics of the relational-database
	normalization. 
	</p>
	
	<p>
	LDBN was developed in order to
give students the ability to easily and efficiently test their knowledge of the different
normal forms in practice. The environment assists the students by providing them the
following functionalities:
<OL>
<LI>Allow the student to specify a candidate decomposition of a given relation.</LI>
<LI>Assess the correctness of the student's proposed decomposition relative to many
factors; including:</LI>
<ul>
<li>Lossless-join property</li>
<li>Dependency preservation</li>
<li>Specification of keys</li>
<li>Correctness of the 2NF, 3NF and BCNF decompositions</li>
</ul>
<LI>Provide students with sample decompositions when needed.</LI>
<LI>Allow users to communicate with each other via comments/posts.</LI>
</OL>
	<p>
	The students can test their knowledge by solving different assignments, 
	which consist of a relational-database schema in
universal-relation form (URF), i.e., all the attributes in a single relation and a set of
FDs on the attributes. The user (the student) have to 
	find different decompositions of the relation. <BR>
	The user can check his solution with LDBN. The result is shown in 
	an information window. The user are given small 
	hints were the mistake might be. If the user is still uncertain about the
	right solution then LDBN can provide him/her with a sample solution as well. 
	</p>
	<p>
	Other features of LDBN include an easy way for lecturers to create 
	new assignments.
	</p>
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